Downwind means in the direction the wind is blowing. If you're standing downwind from a campfire, the smoke drifts toward you because you're positioned where the wind is carrying it. If you're upwind from the fire, the smoke blows away from you.

Animals use this principle constantly. A deer feeding in a meadow will try to stay downwind from where it thinks danger might come, so a predator's scent will blow toward the deer as a warning. Hunters know this too, which is why they approach from the downwind side, keeping their scent from reaching their prey.

In sailing, moving downwind means sailing in the same direction the wind blows, which lets you travel fast with the wind pushing you along. Going upwind requires clever maneuvering because you're fighting against the direction the wind wants to take you.

You might hear someone say they caught a smell from downwind, meaning the wind carried the scent to them from wherever it originated. The word helps us understand how air movement affects everything from forest fires to weather patterns to why your neighbor's barbecue smells so good on a breezy afternoon.